Su KH, Yu YB, Hou HH, Zhao JF, Kou YR, Cheng LC, Shyue SK, Lee TS. AMP-activated protein kinase mediates erythropoietin-induced activation of endothelial nitric oxide synthase.
J Cell Physiol 2012;
227:3053-62. [PMID:
22021095 DOI:
10.1002/jcp.23052]
[Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We investigated whether AMP-activated protein kinase (AMPK), a multi-functional regulator of energy homeostasis, participates in the regulation of erythropoietin (EPO)-mediated activation of endothelial nitric oxide synthase (eNOS) in endothelial cells (ECs) and mice. In ECs, treatment with EPO increased the phosphorylation of AMPK, acetyl-CoA carboxylase (ACC), and eNOS, as revealed by Western blot analysis. Inhibition of AMPK activation by compound C or dominant-negative AMPK mutant abrogated the EPO-induced increase in the phosphorylation of AMPK, ACC, and eNOS, as well as nitric oxide (NO) production. Additionally, suppression of AMPK activation abolished EPO-induced EC proliferation, migration and tube formation. Immunoprecipitation analysis demonstrated that AMPK mediated the EPO-induced increase in the phosphorylation of β common receptor (βCR) and the formation of a βCR-AMPK-eNOS complex. In mice, inhibition of AMPK activation by compound C markedly decreased EPO-elicited angiogenesis in Matrigel plugs. Furthermore, the phosphorylation of AMPK and eNOS was significantly higher in aortas from EPO transgenic mice than wild-type mice. Moreover, treatment with EPO neutralizing antibody greatly reduced the exercise training-induced increase in phosphorylation of AMPK and eNOS in aortas of wild-type mice. Taken together, EPO may trigger AMPK-dependent signaling, which leads to enhanced phosphorylation of βCR and eNOS, increased βCR-AMPK-eNOS complex formation, NO production, and, ultimately, angiogenesis.
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